The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 24, 1991
Filed:
Oct. 12, 1990
Michael C Lea, Harlow, GB;
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Abstract
Apparatus and imaging method in which an LED exposure apparatus having an array of light emitting diodes stationed in a light exposing relationship to a photosensitive material to be imaged is calibrated to take into account the wavelength difference between light emitting diode emissions and the spectral sensitivity of the photosensitive medium. The exposure apparatus is calibrated by making separate energy measurements of each light emitting diode with a detector through a colored filter. The spectral response of the detector and filter combination matches that of the photosensitive material in the wavelength region of the emission of the light emitting diode. The energy measurement are used to modulate each exposure level of the array of light emitting diodes. The calibration method is used during exposure of the photosensitive material by the array of light emitting diodes, particularly for grey scale imaging. The detector and filter are used to modulate exposure in response to the energy measurements.